Lecs 7-10

Question 1

Define Community

Answer 1

a set of interacting species that co-occur in space and time

Question 2

Define Assemblage

Answer 2

a set of species that co-occur in space and time

Question 3

Define Functional groups

Answer 3

assemblage of species that either perform similar activities or work together to perform a specific ecological function

Question 4

Define Guild

Answer 4

a set of species that co-occur in space and time and exploit the same class of resources in a similar way

Question 5

Neutral Assembly Model

Answer 5

Communities are the result of random events of extinction and dispersal of species
-Species equivalent in all ways

Question 6

Niche Assembly Model

Answer 6

Community is the result of interactions among species that are adapted to a particular environment
Species patterns driven by match between species traits and environment

Question 7

Stochastic model vs Deterministic model

Answer 7

Stochastic model: Chance plays a big part in what species are present
Deterministic model: Species niches determine dynamics

Question 8

Intraspecific vs Interspecific competition

Answer 8

Intraspecific competition: between individuals of same species
Interspecific competition: between individuals of different species

Question 9

What is Competitive Exclusion

Answer 9

-A species outcompetes another species, causing their extinction in the community
-Important to Niche Assembly Model

Question 10

PARADOX OF THE PLANKTON

Answer 10

Reasons why it is not a paradox:
-Not a homogeneous environment across time and space
-Species tolerance/optima more unique than taxonomy infers
-Competition not important most of the time
-Resource availability more important

Question 11

Environmental Specialization

Answer 11

Each species has a unique set of environmental requirements

Question 12

Habitat partitioning

Answer 12

Specializing in a specific habitat space to reduce competition with similar species

Question 13

What are the different defenses against predation?

Answer 13

-Behavioral defenses (migration, swarming, escape)
-Morphological defenses (thick shells, long spines)
-Cyclomorphosis (seasonal morphological changes)

Question 14

T/F Changes in behaviour, morphology, and life-history can be induced by environmental signals

Answer 14

True;
ex. change in photoperiod
Food concentration
Chemical signal from a predator (kairomones)

Question 15

What is KEYSTONE PREDATOR

Answer 15

-A Keystone predator is a selective predator on the most competitive prey species
-Associated with increased species diversity

Question 16

This is an example of:
Planktivorous fish that specialize in eating large-bodied zooplankton like Daphnia allows other zooplankton and algae species to proliferate

Answer 16

Keystone Predator

Question 17

Level of community diversity in a lake depends on:

Answer 17

-Lake type
-Lake size & proximity to other lakes
-Taxonomic group
-Sampling protocol

Question 18

Define Pioneer species

Answer 18

-species that arrive first and colonize
-typically good dispersers

Question 19

Aquatic invasive species can:

Answer 19

-Reduce the natural biodiversity and populations of native species through:
-predation, parasitism or competition (for food or space)
-degradation or destruction of ecosystems and fish habitat

Question 20

How can aquatic invasive species harm recreational activities?

Answer 20

damaging infrastructure
invading key recreational areas
pushing out native species from recreational fishing areas
making water unclean for swimming

Question 21

How can aquatic invasive species harm native species?

Answer 21

parasitizing or preying upon native species, as does the sea lamprey
carrying viruses or bacteria that may cause diseases in other species

Question 22

What are the impacts of zebra and quagga mussels?

Answer 22

-Increased water clarity via filter-feeding
-Alters N and P cycling (Nutrient shunt)
-Changes pelagic and benthic community structure
-Increases bottom-feeding fish abundance
-Reduces unionid clam abundance

Question 23

What is Diel vertical migration

Answer 23

-Zooplankton avoid their predators through diel vertical migration
-Typical pattern is to remain in deeper, darker water during the day and rise at night to feed on the algae of the warmer epilimnion
-Effective against fish predation

Question 24

What is Diel Stream Drift (DSD)

Answer 24

-Insect Larvae attached/below benthic substrate detach and drift downstream
-Drift occurs 10x as much at night than during the day

Question 25

Autochthonous vs Allochthonous organic carbon

Answer 25

AUTOCHTHONOUS ORGANIC CARBON
produced within the system
algae, macrophytes

ALLOCHTHONOUS ORGANIC CARBON
produced outside the system
leaves, wood, leachate

Question 26

What is Photosynthesis to Respiration (P/R) Ratio

Answer 26

A common measure of the trophic status of a system is the ratio of gross primary production to community respiration
If P/R ratio is >1, the system is autotrophic
If P/R ratio is <1, the system is heterotrophic

Question 27

Define Secondary production

Answer 27

-the generation of biomass of heterotrophic (consumer) organisms in a system.
-Driven by transfer of organic material between trophic levels

Question 28

Define MICROBIAL LOOP

Answer 28

-The microbial loop is simply a model of the pathways of carbon and nutrient cycling through microbial components of pelagic aquatic communities
-Protists and zooplankton are the most important microbial consumers and have major functions in organic carbon utilization and nutrient recycling.